(function (draftwidth, n) {
    function getRem() {
        var width = document.documentElement.clientWidth
        var html = document.querySelector('html')
        var m = (width / draftwidth) * n
        html.style.fontSize = m + 'px'
    }
    getRem()
    window.addEventListener('resize', function () {
        getRem()
    })
})(1920, 100)